The present invention relates to suspensions or suspension assemblies, at least a portion of which may be assembled using techniques not primarily reliant on welding, brazing, or the use of an adhesive.
In a dynamic storage device, a rotating disk is employed to store information in small magnetized domains strategically located on the disk surface. The disk is attached to and rotated by a spindle motor mounted to a frame of the disk storage device. A xe2x80x9chead sliderxe2x80x9d (also commonly referred to simply as a xe2x80x9csliderxe2x80x9d) having a magnetic read/write head is positioned in close proximity to the rotating disk to enable the writing and reading of data to and from the magnetic domains on the disk. The head slider is supported and properly oriented in relationship to the disk by a head suspension that provides forces and compliances necessary for proper slider operation. As the disk in the storage device rotates beneath the slider and head suspension, the air above the disk similarly rotates, thus creating an air bearing which acts with an aerodynamic design of the head slider to create a lift force on the head slider. The lift force is counteracted by the head suspension, thus positioning the slider at a height and alignment above the disk which is referred to as the xe2x80x9cfly height.xe2x80x9d
Some head suspensions can include a loadbeam, a flexure, and a base plate. The loadbeam normally includes a mounting region at a proximal end of the loadbeam for mounting the head suspension to an actuator of the disk drive, a rigid region, and a spring region between the mounting region and the rigid region for providing a spring force to counteract the aerodynamic lift force acting on the slider described above. The base plate is mounted to the mounting region of the loadbeam to facilitate the attachment of the head suspension to the actuator. The flexure is positioned at the distal end of the loadbeam, and typically includes a gimbal region having a slider mounting surface to which the slider is mounted and thereby supported in read/write orientation with respect to the rotating disk. The gimbal region is resiliently moveable with respect to the remainder of the flexure in response to the aerodynamic forces generated by the air bearing.
In one type of head suspension, the flexure is formed as a separate component and further includes a loadbeam mounting region that is rigidly mounted at the distal end of the loadbeam using conventional means, such as spot welds. In such a flexure, the gimbal region extends distally from the loadbeam mounting region of the flexure and includes a cantilever beam to which the slider is mounted. A generally spherical dimple that extends between the loadbeam and the slider mounting surface of the flexure is formed in either the loadbeam or the slider mounting surface of the flexure. The dimple transfers the spring force generated by the spring region of the loadbeam to the flexure and the slider to counteract the aerodynamic force generated by the air bearing between the slider and the rotating disk. In this manner, the dimple acts as a xe2x80x9cload pointxe2x80x9d between the flexure/slider and the loadbeam. The load point dimple also provides clearance between the cantilever beam of the flexure and the loadbeam, and serves as a point about which the slider can gimbal in pitch and roll directions in response to fluctuations in the aerodynamic forces generated by the air bearing.
Electrical interconnection between the head slider and circuitry in the disk storage device is provided along the length of the head suspension. Conventionally, conductive wires encapsulated in insulating tubes are strung along the length of the head suspension between the head slider and the storage device circuitry. Alternatively, an integrated lead head suspension, such as that described in commonly assigned U.S. Pat. No. 5,491,597 to Bennin et al., that includes one or more conductive traces bonded to the loadbeam with a dielectric adhesive can be used to provide electrical interconnection. Such an integrated lead head suspension may include one or more bonding pads at the distal end of the traces to which the head slider is attached and that provide electrical interconnection to terminals on the head slider. The conductive trace can also be configured to provide sufficient resiliency to allow the head slider to gimbal in response to the variations in the aerodynamic forces.
As the number and density of magnetic domains on the rotating disk increase, it becomes increasingly important that the head slider be precisely aligned over the disk to ensure the proper writing and reading of data to and from the magnetic domains. Moreover, misaligriments between the head slider and the disk could result in the head slider xe2x80x9ccrashingxe2x80x9d into the disk surface as the slider gimbals due to the close proximity of the head slider to the rotating disk at the slider fly height.
The joining of the loadbeam to the actuator arm and the flexure to the loadbeam have been accomplished in various ways, including spot welding. One problem associated with spot welding is the desire to spot weld two members composed of the same material. For example, two members made of steel will generally be better joined together with spot welding than if one of the members were composed of aluminum and the other of steel. The same is seen when spot welding polymeric materials. This can create an undesirable limitation, that being, the need or motivation to use members of the same composition rather than dissimilar composition. This is undesirable because the use of dissimilar compositions can allow for different material properties, desired interfacial relationship between dissimilar materials, and/or cost reductions.
Another joining technique can include the use of a joining material or a joining member to join two members. Such techniques include the use of an adhesive, a soldering material, or a mechanical fastening piece or clip. Introduction of a joining material or member, however, can add undesired complexity to one or more aspects of inventory, assembly, use, and repair relating to the suspension member.
Consequently, there is a need for a suspension design and/or assembly technique that addresses the above-mentioned undesirable results. Such a design and/or assembly technique could be useful with the above-described suspension as well as unamount-type suspensions, which include discrete arms.
The present invention addresses problems not addressed by the prior art. One embodiment of the invention includes a method for making an actuator assembly for supporting a read/write device in an information storage device. It includes providing a actuator arm having at least one tower on a first arm surface of the actuator arm. Another step involves providing a loadbeam comprising tower receiving means for receiving the at least one tower. Another step is placing the loadbeam onto the actuator arm such that the at least one tower is received by the tower receiving means. Still another step is deforming the tower to provide a deformation interference between the at least one tower and the tower receiving means and reduce lifting of the loadbeam from the actuator arm where the interference occurs.
The actuator arm and the tower may be comprised of a first metal and the loadbeam is comprised of a second metal. The first metal could be different from the second metal. The first metal could be aluminum and the second metal could be steel, such as stainless steel.
The loadbeam can have a first loadbeam surface. The previously noted difference between the first and second metals prevents or complicates attaching the loadbeam to the actuator arm by spot welding, ultrasonically welding, or other welding of the first loadbeam surface to the first arm surface.
The previously-noted tower receiving means can be a first loadbeam surface having a hole through which the at least one tower protrudes after the placing step.
The previously noted at least one tower could include, rather, a plurality of towers. The tower receiving means can include a first loadbeam surface having a plurality of holes through which the plurality of towers protrude after the placing step. The hole and the tower may each have a generally circular shape or an elongated shape or some other shape.
The previously-noted actuator arm can further include an arm registering means. The loadbeam can further include a loadbeam registering means. Such an arm registering means could have a first arm registering hole therethrough, and such loadbeam registering means could have a first loadbeam registering hole therethrough. The method could further comprise the step of placing the arm and loadbeam onto an assembly fixture having a first registering member such that the first registering member protrudes through the first arm registering hole and through the first loadbeam registering hole.
The arm registering means can further have a second arm registering hole therethrough. The loadbeam registering means can have a second loadbeam registering hole therethrough. The assembly fixture can further have a second registering member. The step of placing the arm and loadbeam onto an assembly fixture can cause the second registering member to protrude through the second arm registering hole and the second loadbeam registering hole.
The previously-noted deforming step comprises the mechanically deforming the tower to provide the deformation interference. The at least one tower can be comprised of a metal and the deforming step can comprise melting the metal to provide the deformation interference. The melting can be accomplished by an application of one of a laser beam, ultrasonic energy, contact with a heated member, and another heating means.
Initial interference can exist between the at least one tower and the tower receiving means before the deforming step.
Still another embodiment of the present invention includes an actuator assembly for supporting a read/write device in an information storage device. It can include an actuator arm having at least one tower protruding from a first surface of the actuator arm. A loadbeam can have at least one tower receiving means for receiving the at least one tower. The at least one tower is shaped to extend into the at least one tower receiving means when the loadbeam is joined with the actuator arm, and wherein the tower and tower receiving means are configured such that deforming the at least one tower when within the at least one tower receiving means provides a deformation interference between the at least one tower and the at least one tower receiving means. This can reduce movement of the tower receiving means relative to the tower.
The actuator arm can have a proximal region and a distal region. The at least one tower can protrude from the first surface within the distal region. The actuator arm can be comprised of a first metal, and the loadbeam can be comprised of a second metal, i.e., different from the first. For example, the first metal can be aluminum and the second metal can be steel, e.g., stainless steel. The at least one tower can have a shape and a composition such that it may be mechanically deformed to provide the deformation interference and allow for performance of the actuator assembly within the information storage device. The tower can have a tower shape and a metal-based composition such that it may be thermally deformed to provide the deformation interference and allow for the performance.
The tower receiving means can include a first loadbeam surface having at least one hole through which the at least one tower protrudes when the loadbeam is placed on the actuator arm. The at least one hole can be a plurality of holes, and the at least one tower can include a plurality of towers. The tower(s) and hole(s) can be circular shaped, elongate shaped, rectangular shaped, triangular shaped, or have a more complex shape.
Still another embodiment of the present invention can be an actuator assembly for supporting a read/write device in an information storage device. It can include an actuator arm having at least one tower protruding from a first surface of the actuator arm. The at least one tower can be configured to be deform when at least one of sufficient heat or sufficient pressure is applied thereto. A loadbeam can have a first loadbeam surface with at least one tower hole into which the at least one tower can be inserted. The at least one tower can be shaped to extend into the at least one tower hole when the loadbeam is joined with the actuator arm. The tower and tower hole are configured such that an application of at least one of sufficient heat or sufficient pressure to the at least one tower results in deformation of the at least one tower that secures the loadbeam to the actuator arm. The at least one tower can include one, two, three, four, or even more towers. And, the at least one tower hole can include a like number.
The tower(s) can, instead, be positioned on the loadbeam with the holes or other receiving means positioned on the actuator arms. Similarly, one or more towers and tower holes can be on one of these components that match up correspondingly with tower holes and towers on the other component.